1 2 /*--------------------------------------------------------------------*/ 3 /*--- The core dispatch loop, for jumping to a code address. ---*/ 4 /*--- dispatch-arm-linux.S ---*/ 5 /*--------------------------------------------------------------------*/ 6 7 /* 8 This file is part of Valgrind, a dynamic binary instrumentation 9 framework. 10 11 Copyright (C) 2008-2013 Evan Geller 12 gaze (at) bea.ms 13 14 This program is free software; you can redistribute it and/or 15 modify it under the terms of the GNU General Public License as 16 published by the Free Software Foundation; either version 2 of the 17 License, or (at your option) any later version. 18 19 This program is distributed in the hope that it will be useful, but 20 WITHOUT ANY WARRANTY; without even the implied warranty of 21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 22 General Public License for more details. 23 24 You should have received a copy of the GNU General Public License 25 along with this program; if not, write to the Free Software 26 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 27 02111-1307, USA. 28 29 The GNU General Public License is contained in the file COPYING. 30 */ 31 32 #if defined(VGP_arm_linux) 33 .fpu vfp 34 35 #include "pub_core_basics_asm.h" 36 #include "pub_core_dispatch_asm.h" 37 #include "pub_core_transtab_asm.h" 38 #include "libvex_guest_offsets.h" /* for OFFSET_arm_R* */ 39 40 41 /*------------------------------------------------------------*/ 42 /*--- ---*/ 43 /*--- The dispatch loop. VG_(disp_run_translations) is ---*/ 44 /*--- used to run all translations, ---*/ 45 /*--- including no-redir ones. ---*/ 46 /*--- ---*/ 47 /*------------------------------------------------------------*/ 48 49 /*----------------------------------------------------*/ 50 /*--- Entry and preamble (set everything up) ---*/ 51 /*----------------------------------------------------*/ 52 53 /* signature: 54 void VG_(disp_run_translations)( UWord* two_words, 55 void* guest_state, 56 Addr host_addr ); 57 */ 58 .text 59 .global VG_(disp_run_translations) 60 VG_(disp_run_translations): 61 /* r0 holds two_words 62 r1 holds guest_state 63 r2 holds host_addr 64 */ 65 /* The number of regs in this list needs to be even, in 66 order to keep the stack 8-aligned. */ 67 push {r0, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, lr} 68 69 /* set FPSCR to vex-required default value */ 70 mov r4, #0 71 fmxr fpscr, r4 72 73 /* Set up the guest state pointer */ 74 mov r8, r1 75 76 /* and jump into the code cache. Chained translations in 77 the code cache run, until for whatever reason, they can't 78 continue. When that happens, the translation in question 79 will jump (or call) to one of the continuation points 80 VG_(cp_...) below. */ 81 bx r2 82 /* NOTREACHED */ 83 84 /*----------------------------------------------------*/ 85 /*--- Postamble and exit. ---*/ 86 /*----------------------------------------------------*/ 87 88 postamble: 89 /* At this point, r1 and r2 contain two 90 words to be returned to the caller. r1 91 holds a TRC value, and r2 optionally may 92 hold another word (for CHAIN_ME exits, the 93 address of the place to patch.) */ 94 95 /* We're leaving. Check that nobody messed with 96 FPSCR in ways we don't expect. */ 97 fmrx r4, fpscr 98 bic r4, #0xF8000000 /* mask out NZCV and QC */ 99 bic r4, #0x0000009F /* mask out IDC,IXC,UFC,OFC,DZC,IOC */ 100 cmp r4, #0 101 beq remove_frame /* we're OK */ 102 /* otherwise we have an invariant violation */ 103 movw r1, #VG_TRC_INVARIANT_FAILED 104 movw r2, #0 105 /* fall through */ 106 107 remove_frame: 108 /* Restore int regs, including importantly r0 (two_words) */ 109 pop {r0, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, lr} 110 /* Stash return values */ 111 str r1, [r0, #0] 112 str r2, [r0, #4] 113 bx lr 114 115 /*----------------------------------------------------*/ 116 /*--- Continuation points ---*/ 117 /*----------------------------------------------------*/ 118 119 /* ------ Chain me to slow entry point ------ */ 120 .global VG_(disp_cp_chain_me_to_slowEP) 121 VG_(disp_cp_chain_me_to_slowEP): 122 /* We got called. The return address indicates 123 where the patching needs to happen. Collect 124 the return address and, exit back to C land, 125 handing the caller the pair (Chain_me_S, RA) */ 126 mov r1, #VG_TRC_CHAIN_ME_TO_SLOW_EP 127 mov r2, lr 128 /* 4 = movw r12, lo16(disp_cp_chain_me_to_slowEP) 129 4 = movt r12, hi16(disp_cp_chain_me_to_slowEP) 130 4 = blx r12 */ 131 sub r2, r2, #4+4+4 132 b postamble 133 134 /* ------ Chain me to fast entry point ------ */ 135 .global VG_(disp_cp_chain_me_to_fastEP) 136 VG_(disp_cp_chain_me_to_fastEP): 137 /* We got called. The return address indicates 138 where the patching needs to happen. Collect 139 the return address and, exit back to C land, 140 handing the caller the pair (Chain_me_F, RA) */ 141 mov r1, #VG_TRC_CHAIN_ME_TO_FAST_EP 142 mov r2, lr 143 /* 4 = movw r12, lo16(disp_cp_chain_me_to_fastEP) 144 4 = movt r12, hi16(disp_cp_chain_me_to_fastEP) 145 4 = blx r12 */ 146 sub r2, r2, #4+4+4 147 b postamble 148 149 /* ------ Indirect but boring jump ------ */ 150 .global VG_(disp_cp_xindir) 151 VG_(disp_cp_xindir): 152 /* Where are we going? */ 153 ldr r0, [r8, #OFFSET_arm_R15T] 154 155 /* stats only */ 156 movw r1, #:lower16:vgPlain_stats__n_xindirs_32 157 movt r1, #:upper16:vgPlain_stats__n_xindirs_32 158 ldr r2, [r1, #0] 159 add r2, r2, #1 160 str r2, [r1, #0] 161 162 /* try a fast lookup in the translation cache */ 163 // r0 = next guest, r1,r2,r3,r4 scratch 164 movw r1, #VG_TT_FAST_MASK // r1 = VG_TT_FAST_MASK 165 movw r4, #:lower16:VG_(tt_fast) 166 167 and r2, r1, r0, LSR #1 // r2 = entry # 168 movt r4, #:upper16:VG_(tt_fast) // r4 = &VG_(tt_fast) 169 170 add r1, r4, r2, LSL #3 // r1 = &tt_fast[entry#] 171 172 ldrd r4, r5, [r1, #0] // r4 = .guest, r5 = .host 173 174 cmp r4, r0 175 176 // jump to host if lookup succeeded 177 bxeq r5 178 179 /* otherwise the fast lookup failed */ 180 /* RM ME -- stats only */ 181 movw r1, #:lower16:vgPlain_stats__n_xindir_misses_32 182 movt r1, #:upper16:vgPlain_stats__n_xindir_misses_32 183 ldr r2, [r1, #0] 184 add r2, r2, #1 185 str r2, [r1, #0] 186 187 mov r1, #VG_TRC_INNER_FASTMISS 188 mov r2, #0 189 b postamble 190 191 /* ------ Assisted jump ------ */ 192 .global VG_(disp_cp_xassisted) 193 VG_(disp_cp_xassisted): 194 /* r8 contains the TRC */ 195 mov r1, r8 196 mov r2, #0 197 b postamble 198 199 /* ------ Event check failed ------ */ 200 .global VG_(disp_cp_evcheck_fail) 201 VG_(disp_cp_evcheck_fail): 202 mov r1, #VG_TRC_INNER_COUNTERZERO 203 mov r2, #0 204 b postamble 205 206 207 .size VG_(disp_run_translations), .-VG_(disp_run_translations) 208 209 /* Let the linker know we don't need an executable stack */ 210 .section .note.GNU-stack,"",%progbits 211 212 #endif // defined(VGP_arm_linux) 213 214 /*--------------------------------------------------------------------*/ 215 /*--- end dispatch-arm-linux.S ---*/ 216 /*--------------------------------------------------------------------*/ 217
